From 68c65bbea6c28676d8f5921d2f75e87ee4ead61c Mon Sep 17 00:00:00 2001
From: Akash Mozumdar <akashmozumdar@gmail.com>
Date: Thu, 27 Jun 2019 12:41:15 +0530
Subject: [PATCH] x64 v8/javascript/tyranobuilder hook

---
 texthook/engine/match32.cc | 12 +++++++++++-
 texthook/engine/match64.cc | 27 ++++++++++++++++++++++++++-
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/texthook/engine/match32.cc b/texthook/engine/match32.cc
index a0bd47a..c98e93e 100644
--- a/texthook/engine/match32.cc
+++ b/texthook/engine/match32.cc
@@ -65,12 +65,22 @@ bool DeterminePCEngine()
 	  else for (int i = 0; i < 50; ++i)
 		  if (HMODULE module = GetModuleHandleW((DXVersion + L"_" + std::to_wstring(i)).c_str())) PcHooks::hookD3DXFunctions(module);
 
-  if (GetProcAddress((HMODULE)processStartAddress, "?Write@String@v8@@QBEHPAGHHH@Z")) 
+  if (GetProcAddress((HMODULE)processStartAddress, "?Write@String@v8@@QBEHPAGHHH@Z"))
+  {
 	  InsertV8Hook((HMODULE)processStartAddress);
+	  return true;
+  }
   if (HMODULE module = GetModuleHandleW(L"node.dll"))
+  {
 	  InsertV8Hook(module);
+	  return true;
+  }
+	 
   if (HMODULE module = GetModuleHandleW(L"nw.dll"))
+  {
 	  InsertV8Hook(module);
+	  return true;
+  }
 
   if (InsertMonoHooks()) {
     return true;
diff --git a/texthook/engine/match64.cc b/texthook/engine/match64.cc
index d4a35a8..6a2144f 100644
--- a/texthook/engine/match64.cc
+++ b/texthook/engine/match64.cc
@@ -90,7 +90,7 @@ namespace Engine
 									HookParam hp = {};
 									hp.address = addr;
 									hp.type = USING_STRING | USING_UNICODE;
-									hp.offset = -0x20;
+									hp.offset = -0x20; // rcx
 									hp.padding = 20;
 									hp.length_fun = [](uintptr_t, uintptr_t data)
 									{
@@ -115,10 +115,35 @@ namespace Engine
 		return ret;
 	}
 
+	// Artikash 6/23/2019: V8 (JavaScript runtime) has rcx = string** at v8::String::Write
+	// sample game https://www.freem.ne.jp/dl/win/18963
+	bool InsertV8Hook(HMODULE module)
+	{
+		if (uint64_t addr = (uint64_t)GetProcAddress(module, "?Write@String@v8@@QEBAHPEAGHHH@Z"))
+		{
+			HookParam hp = {};
+			hp.type = USING_STRING | USING_UNICODE | DATA_INDIRECT;
+			hp.address = addr;
+			hp.offset = -0x20; // rcx
+			hp.index = 0;
+			hp.padding = 23;
+			hp.length_fun = [](uintptr_t, uintptr_t data)
+			{
+				int len = *(int*)(data - 4);
+				return len > 0 && len < 1000 ? len * 2 : 0;
+			};
+			NewHook(hp, "JavaScript");
+			return true;
+		}
+		return false;
+	}
+
 	bool UnsafeDetermineEngineType()
 	{
 		if (Util::CheckFile(L"PPSSPP*.exe") && FindPPSSPP()) return true;
 
+		for (const wchar_t* moduleName : { (const wchar_t*)NULL, L"node.dll", L"nw.dll" }) if (InsertV8Hook(GetModuleHandleW(moduleName))) return true;
+
 		for (const wchar_t* monoName : { L"mono", L"mono-2.0-bdwgc" }) if (HMODULE module = GetModuleHandleW(monoName)) if (InsertMonoHooks(module)) return true;
 
 		for (std::wstring DXVersion : { L"d3dx9", L"d3dx10" })